Peripheral neuroepithelioma in childhood. Immunohistochemical demonstration of epithelial differentiation.

Peripheral neuroepithelioma arising from the chest wall of a 4-year-old girl is described. She died of local recurrence 15 months after surgery. Light- and electron-microscopic as well as immunohistochemical findings confirmed the neuroectodermal nature of the tumor. A distinctive histologic feature was the presence of clustered epitheliallike cells, which immunohistochemically stained positive for both keratin and carcinoembryonic antigen. The epithelial nature of these peculiar cells is presented.